Abstract

Chlorpromazine hydrochloride (CPZ) a widely used tranquilizer was earlier shown to preferentially sensitize hypoxic bacterial cells to 60Co gamma rays (Shenoy, George, Singh & Ayengar, 1975). CPZ was also observed to be toxic towards hypoxic cells (Shenoy & Singh, 1978) and this hypoxic cytotoxicity was found to be dependent on temperature. When tested in murine tumors, the drug sensitized Sarcoma 180A (Shenoy & Singh, 1980) as well as fibrosarcoma (George Srinivasan & Singh, 1980) to x-rays. A marked chemotherapeutic effect of CPZ was evident in Sarcoma 180A (Shenoy & Singh, 1980) and this effect was more pronounced in clamped tumors (George et al., 1980), indicating the effectiveness of the drug when cells were under acute hypoxia.